SPE Library
The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.
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Conference Proceedings
Layered, Nano Foams from PS Blends
X. Liao, A.V. Nawaby, P. Handa, May 2006
This paper reports on the single-phase blend of polystyrene with syndiotactic polystyrene, its fluid phase behavior with CO2, and on the layered and nano foams obtained therefrom.
Experimental Studies and Modeling of Fiber Breakage in Co-Rotating Twin Screw Extruder
Sughun Bumm, Kyunha Ban, James L. White, May 2006
An experimental study of glass fiber breakage in corotating twin screw extruder for isotactic polypropylene and polyamide12 is presented. Comparisons are made using different screw configurations, fiber length, diameter, and loading. We have developed a model for the kinetics of fiber breakage and evaluated the kinetic constants for various conditions.The glass fiber breaks up and the fiber length was reduced to a steady state length. The steady state length primarily depends on the screw configurations and initial fiber length.
Mechanical Properties of PP/Ethylene Acrylate Copolymer/TiO2 Blends
Xiyun S. Fan, May 2006
An ethylene methyl acrylate copolymer (EMA) produced from a tubular reactor was found to be effective in toughening polypropylene even at low concentrations. The addition of a small amount of TiO2 pigment enhanced the EMA toughening effect. Microscopy and thermal analysis helped to reveal the possible EMA toughening mechanisms. The effects of two processing methods, dry-blending and melt-blending, on the compound mechanical properties were also studied.
Structure Development In Melt Spinning the New Generation of Polyolefins
Haifeng Shan, James L.White, Dongman Choi, May 2006
In the period of the late 1930s to the 1950s, the first generation of polyolefins including polyethylene, isotactic polypropylene and other isotactic polyolefins were introduced. The structures developed in these polymer have since that time been investigated. In the 1990s, polypropylene of various tacticities and new copolymers of ethylene with varying compositions have been introduced. We describe here studies of the structure development of these new polymers during melt spinning processing.
Reactive Extrusion of PBT for Low Density Foaming
B. Jeong, M. Xanthos, K. Hyun, May 2006
Branching or partial cross-linking of polybutylene terephthalate (PBT) resins by reactive modification with multi-functional epoxides was investigated. The rheology of the PBT products could be controlled by varying material and operational conditions of the reactive extrusion process. The modified PBT was adaptable to low density foam extrusion, where higher melt strength is necessary.
Application of Recycled Industrial Polyolefins in Pail Design Using FEM
S. Haider Rizvi, S.H. Masood, Igor Sbarski, May 2006
This paper presents the application of recycled industrial HDPE and PP and their blends with virgin resins in pail design using finite element analysis. Results predict that these blends can be used in pails for the packaging of non food grade materials such as paints, oil and grease.
Interfacial Adhesion in Bamboo Fiber/Biodegradable Polymer Composites
M. Nakamura, K. Kitagawa, H. Okumura, U.S. Ishiaku, M. Kotaki, H. Hamada, May 2006
Surface treatment with natural resin on bamboo fibers is hypothesized to improve the interfacial adhesion between bamboo fibers and biodegradable polymers. Effect of the surface treatment on the interfacial adhesion was investigated by evaluation of mechanical properties and fracture behavior of the composites.
Carbon Composite Bipolar Plates for Fuel Cell
Sun Ho Park, Chang Min Hong, Young Jun Lee, May 2006
The shape and intrinsic conductivity of conductive fillers affect to performance of bipolar plate, therefore the effect of conductive fillers and morphology of polymer/ conductive filler composites on conductivity were evaluated to utilize in fuel cell. The mixture of conductive fillers such as graphite/carbon black, graphite/carbon nanofiber, and graphite/carbon nanotube were also estimated to minimize the loading of conductive fillers in bipolar plates.
Investigation of PPA Interactions with Polymer Melts in Coextrusion Flows
M. Zatloukal, J. De Witte, C. Lavallée, May 2006
Recently proposed new slip model based on 'effective continuum methods' was developed and used for investigation of process aids interactions with polymer melts in single as well as multi-layer flows. Specific attention has been paid to understanding the role of process aids on stabilization of the zig-zag type of interfacial instabilities in film blowing coextrusion.
Modeling of Viscoelastic Multi-Layer Flows for Different Polymer Melts
M. Zatloukal, M.T. Martyn, J. Vlcek, P.D. Coates, May 2006
Modified Leonov model has been employed in the modeling of the coextrusion flows with same as well as differerent polymer melts. Flow visualization measurements were used for verification of the used numerical scheme. Specific attention is paid here to the possible numerical difficulties which may occur during modeling of the merging area with different polymer materials. Both, measurements as well as FEM analysis of the coextrusion flows were discussed from the wave type of interfacial instabilities point of view.
Investigation of Advanced Constitutive Equations Under Different Flow Conditions
M. Zatloukal, R. Pivokonský, T. Gough, P.D. Coates, May 2006
The predictive capabilities of three models (eXtended Pom-Pom, PTT- XPP and modified Leonov model) are tested for both, steady as well as transient shear and uniaxial extensional flows of LDPE. In the second part of the paper, the modified Leonov model is employed in FEM modeling of the abrupt contraction flow and predicted stress fields are compared with the stress measurements from the flow visualization cell.
The Elimination of Weld Line Witness Marks in Injection Moulding
Peter S. Allan, Keith W. Rawson, Michael J. Bevis, May 2006
The surface witness marks of weld lines in injection mouldings can be particularly unsightly in certain resin compounds. This paper will describe a method that offers the potential to eliminate weld line witness marks. The process involves the combination of selectively heating the mould surface and the application of melt shearing in the mould cavity.
Shape Memory Binary Blends: Compositionally Tailored Fixing and Recovery
Cheryl J. Campo, Patrick T. Mather, May 2006
Semicrystalline-amorphous blends exhibit shape memory due to (1) the elastomeric nature imparted by crystallites that act as physical crosslinks and (2) temporary shape fixing made possible by the vitrification of a continuous, miscible amorphous phase. PVDF-containing binary blends were studied using calorimetry and rheology in order to characterize the morphological control afforded by subjecting such materials to different thermal histories. The sensitivity of the aforementioned techniques to changes in blend morphology will also be discussed.
Fracture Behaviour of Injection Moulding Post-Consumer Wood/Plastic Composite Foams
R. Gosselin, B. Riedl, D. Rodrigue, May 2006
This study investigates fibre reinforced microcellular foams produced via injection moulding using recycled polymers. The objective is to determine the effect of wood, blowing agent and coupling agent contents on impact and tensile properties. Birch wood fibres were blended with a post-consumer HDPE/PP matrix to produce the composites. Azodicarbonamide was used as a blowing agent while maleic anhydride polypropylene copolymer was used as a compatibilizer. Optimal results were obtained with 20 wt.% wood contents.
The Effect of Sharp Corners and Runner Length on Melt Flow Imbalances
Raymond W. McKee, Joshua A. Hoover, May 2006
This study revealed that the use of 90 degree sharp corners has virtually no effect on mold filling imbalance. The study also found that mold fill rates can have a significant impact on the shear induced imbalances found in multi-cavity molds. Further, the study found that increasing the length of the secondary runner will initially decrease the shear induced imbalance developed in the primary runner. Continuing to increase the length has a diminishing effect on the degree the imbalance decreases.
Film-Casting Behavior as a Function of Molecular Structure and Rheology
Christopher W. Seay, Donald G. Baird, May 2006
Polyethylene resins with different molecular structures and rheological properties are investigated in terms of their performance in film-casting. Four metallocene catalyzed polyethylene resins with different degrees of long-chain branching and two conventional polyethylene resins are analyzed in terms of their dimensional changes during film production. With an increase in long-chain branching, and thus strain hardening-behavior, an increase in the necking phenomenon is observed during film-casting.
Antimicrobial Additives in Medical Plastics Compounds
Lawrence A Acquarulo, Jr., Lawrence Johnson, Anthony Listro, Charles J. O’Neil, May 2006
Bacterial infections in hospitals are a leading cause of death in the U.S. and can be caused by bacterial growth on plastic medical devices. The purpose of this paper is to identify effects of microorganisms on plastics, discuss pros and cons of antimicrobial additives in medical plastics.
Measurement of Surface Properties of Polymeric Materials Using Nanosphere Embedment Measurements
Stephen A. Hutcheson, Gregory B. McKenna, May 2006
Here we report results from our ongoing investigation of the surface properties of polymers using a nanoparticle embedment method that was originally pioneered by Teichroeb and Forrest. We describe a viscoelastic contact mechanics solution that includes surface adhesive forces and a time dependent Poisson's ratio. The results show that, with properly designed experiments, both the surface adhesion properties and the surface rheological properties can be extracted from nanosphere embedment measurements.
A Test Method for Rolling Resistance of Rubber Compounds
A.N. Gent, May 2006
A test method is described for measuring energy losses in rolling, using the damped oscillations of a pendulum. The amplitude of oscillation decays initially at a constant rate, and changes to a decreasing rate as the swings become small. In principle, the two processes provide separate measures of energy dissipation. The proposed method could be used for studying the effects of surface features of tire treads and roads on tire rolling resistance, in addition to characterizing the dissipative properties of tread compounds.
Mechanical Properties of Foamed PP Sheet
Yasuhiro NISHIKAWA, Xinyu YANG, Seiichiro HISAKA, Asami NAKAI, Hiroyuki HAMADA, May 2006
Mechanical properties of foamed polypropylene sheet having different foaming ratios (2.0, 2.4 and 3.0) were investigated. Tensile strengths and ultimate strains of polypropylene sheet with 3.0 foaming ratio were lower than those of polypropylene sheet with 2.0 and 2.4 foaming ratios. The ultimate strain increased with an increase in the aspect ratio of the cell shape in the polypropylene sheet. The ultimate strain of the foamed polypropylene sheet was affected by the cell shape.
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